Modeless Interaction Techniques for Text Editing
1. Modeless Interaction Techniques for Text Editing Larry Tesler for Interaction Techniques CMU HCII ! 5 Feb 2014
2. The User Experience in 1960 Source: http://www.columbia.edu/acis/history/650.html
3.Doug Engelbart’s 1968 NLS Demo Source: http://dougengelbart.org/images/pix/img0029.jpg
4.An NLS Workstation circa 1969 Source: http://dougengelbart.org/images/pix/wke.jpg
5. [Xerox] PARC — Founded 1970 Source: Wikimedia Commons. Photo by Coolcaesar.
6.Me and my Alto at PARC in 1975
7. Early Mice SRI 1963 1968 Telefunken 1968 1972 Xerox PARC 1973 Image sources: dougengelbart.org, oldmouse.com, Wikimedia Commons
8.User Studies I ran in 1973 The main subject was our secretary Blank screen study findings included: She wanted and expected WYSIWYG To delete [imaginary] text she would run her finger across it on the screen and press a Delete key (verb after object) Studies of RCG (an NLS subset) Syntax was verb before object
9. NLS and RCG delete syntax verb noun mark OK Delete Character Word Statement Text (2 marks)
10. NLS and RCG editing syntax verb noun mark OK Delete Character Move Word Insert Statement mark Replace Text (2 marks)
11.RCG user study Aug 1973
12.Conclusions that endured Character keys type characters, not commands The intuitive use of a mouse is to point at things, not to accept and delete commands There is a “cursor” displayed showing where the next character typed will appear There are two ways to move the cursor: keystrokes and mouse pointing
13.Conclusions we abandoned There are no invisible characters; carriage return is a command, not a character Space bar and carriage return should do what they do on typewriters Keys that don’t exist on typewriters do nothing until the user has learned them The mouse is taught late; its best aspects are emphasized to make a positive impression
15.Design done with Jeff Rulifson
16.Design done with Jeff Rulifson
17.Objections to cut & paste 1. Unfamiliar metaphor (in the ‘60s and ‘70s) 2. User mistakes (e.g., forgot to paste) 3. Speed compared to NLS 4. Extensibility to other applications
18.Advantages of cut & paste 1. Fewer errors because there can’t be any mode errors.
19.Advantages of cut & paste 1. Fewer errors because there can’t be any mode errors. 2. Speed. Roberts and Moran (1983) showed that experienced Gypsy users, on average, performed tasks in two-thirds the time of NLS. Fewer key presses were required.
20. Roberts & Moran Results Source: “The evaluation of text editors: methodology and empirical results” by Teresa L. Roberts and Thomas P. Moran, CACM 26(4) April 1983 pp. 265-283
21.Advantages of cut & paste 1. Fewer errors because there can’t be any mode errors. 2. Speed. Roberts and Moran (1983) showed that experienced Gypsy users, on average, performed tasks in two-thirds the time of NLS. Fewer key presses were required. 3. Modeless. The ability to do other things between cut and paste entails more benefits than risks.
22.What is a mode? A mode is a state of the user interface that lasts for a period of time, is not associated with any particular object, and has no role other than to place an interpretation on operator input.
23.Prefix vs. suffix syntax in editors Prefix Syntax <verb> <object> After the verb, the editor must enter a mode to wait for the user to specify the object. Suffix Syntax <object> <verb> After the verb, the editor can perform the command immediately. No mode is needed.
24.How modes degrade usability ! Keeping track of mode changes can distract a user from the task at hand. If the current mode is misjudged, unintended and sometimes disastrous results ensue. Users often get “stuck” in a mode and ask, “How do I get out of this mode?”
25.Image source: Gypsy manual, Xerox PARC
26. Modeless Search, Move and Copy Image source: Gypsy manual, Xerox PARC
27. Modeless Search, Move and Copy Image source: Gypsy manual, Xerox PARC
28. Modeless Search, Move and Copy Image source: Gypsy manual, Xerox PARC